1. Field of the Invention
The present invention relates to a lateral pipe-lining method for lining a lateral pipe using a lateral pipe-lining material impregnated with a curable resin having a flange formed at one end thereof, and a flange-pressing implement for a lateral pipe-lining material used in the lateral pipe-lining method.
2. Description of the Related Art
Known in the art are pipe-lining methods for lining the internal peripheral surface of aging sewer pipes or other pipes buried underground so that they can be repaired without having to be dug from the ground.
These methods employ a pipe-lining material having a flexible tubular resin-absorbing material impregnated with a curable resin that is covered with a highly airtight film on the exterior thereof. The pipe-lining material is everted and inserted into the pipe using hydrostatic pressure. The pipe-lining material is heated while being pressed against the internal peripheral surface of the pipe by the hydrostatic pressure, and the resin impregnated in the pipe-lining material is cured, thereby lining the internal peripheral surface of the pipe.
Such a method can be applied to a lateral pipe that branches from a main pipe, as described in Japanese Laid-open Patent Application Nos. 1992-355115 and 2008-168468. When a lateral pipe is to be lined, a lateral-pipe lining material with a flange formed at one end thereof is prepared and housed in a pressure bag. The flange of the lateral pipe-lining material is positioned on a head collar of a work robot introduced inside the main pipe and is brought into close contact with the lateral pipe opening in the main pipe by driving the work robot. Compressed air is fed inside the pressure bag to evert and insert the lateral pipe-lining material into the lateral pipe. When the pipe-lining material is everted and inserted throughout the entire length of the lateral pipe, the lateral pipe-lining material is kept pressed against the internal peripheral surface of the lateral pipe and heated to cure the impregnated thermosetting resin. The internal peripheral surface of the lateral pipe is lined by the lateral pipe-lining material thus cured.
The flange of the lateral pipe-lining material is usually impregnated with a thermosetting resin and previously cured when it is manufactured in the factory. Alternatively, the flange of the lateral pipe-lining material is made of a thermoplastic resin. In either case, the flange of the lateral pipe-lining material lacks flexibility at room temperature. Therefore, an adequately close contact with the periphery of the lateral pipe opening of the main pipe cannot be achieved when there is a manufacturing error in the flange or when there are concavities and convexities in the periphery of the lateral pipe opening of the main pipe.
In these cases, gaps are disadvantageously produced between the flange of the lateral pipe-lining material and the periphery of the lateral pipe opening of the main pipe when lining is complete. Underground water as well as earth and sand from the ground flow into the main pipe via the gap, and the drainage performance of the main pipe is degraded.